Note: It is usually best that a condolence letter is written on personal stationary or in a card. Handwritten letters seem more personal and sincere, even from business colleagues or partners. It is appropriate to send such a letter with flowers or a gift basket.
I am writing to express my sincerest condolences to you after learning of the passing of [Deceased's Name]. I know this is an uncertain and emotionally difficult time for you and your family. Both I and the rest of our colleagues send you our thoughts and prayers.
Though I didn't know [Deceased's Name] I know how important he was to you and your loved ones. Hearing the stories about how hard he worked in his life and how much joy he brought you made me feel like I did know him. His memory will no doubt live on through loved ones like you and your family.
Grief is never easy. Please take care of yourself and your family. We are here to support you during this difficult time. Please let me know to where we can send flowers and any information about services that you might want to share.